Methods :
A total of 29 subjects with CONH (6-66 years old) and 64 normal subjects (6-64 years old, age and race-matched) were recruited. All CONH subjects had comprehensive eye exams prior to enrollment and were diagnosed with either unilateral or bilateral CONH, resulting in a total of 39 CONH eyes. Cirrus SD-OCT 5000 was performed on all subjects. OCT images were unobtainable in one subject with bilateral CONH (thus, 37 CONH eyes were included). Only right eye data from control subjects were used for data analysis. One-way analysis of variance was used to determine whether the OCT parameters differed among the CONH, fellow, and control eyes.

Results :
OCT parameters in CONH, fellow, and control eyes are listed in Table 1. There were significant differences in all OCT parameters among the three groups, including disc area, rim area, C/D ratio, RNFL thickness, and macular ganglion cell measurements (P values in Table 1). Post hoc tests showed statistically significant differences in all OCT parameters between CONH and control eyes, but not between fellow and control eyes. Optic disc parameters were statistically significantly different between CONH and fellow eyes; however the difference in RNFL and macular ganglion cell measurements between CONH and fellow eyes did not reach statistical significance.

Conclusions :
Abnormal Cirrus SD-OCT parameters discriminated between eyes with and without CONH. CONH eyes were characterized with smaller disc area, rim area and C/D ratio as well as reduced RNFL and macular ganglion cell thickness compared to the control eyes.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.